As known, keyboards are indispensable input devices for people in the modern societies to operate computers. Generally, plural keys are installed on a top surface of the keyboard. Via the keyboard, the user can press one or more keys to input a command.
With increasing development of keyboards, a keyboard with a backlight module has been prevailing in the market. The keyboard with the backlight module is also referred as a luminous keyboard. When the luminous keyboard is used in an indoor lighting environment such as an office or a room, the human eyes can obviously recognize that the light beam from a bottom side of the luminous keyboard illuminates all keys of the luminous keyboard. Consequently, a visual effect is generated.
Generally, the backlight module comprises a light-shading plate, a light guide plate and a reflecting plate. The light guide plate is clamped between the light-shading plate and the reflecting plate. Consequently, the light beam is restrainedly transmitted within the light guide plate and outputted from specified light-outputting zones. Moreover, due to the arrangements of cables or inner structures of the keyboard, some openings are formed in specified positions of the backlight module. The cables or the inner structures are penetrated through the corresponding openings. However, since the cable or the inner structure is usually thinner than the opening, the opening cannot be completely shaded by the volume of the cable or the inner structure. The light beam is possibly leaked out from the positions of the backlight module corresponding to the openings.
Therefore, the conventional luminous keyboard needs to be further improved.